engleski

XRD structural investigations of selected technologically attractive nanomaterials: transparent conducting oxides, doped optoelectronic and luminescent materials, doped ceramics

The preparation and application of novel materials tend toward sophisticated micro- and nanotechnologies. However, several properties of the novel nanomaterials have still not been well explained. The main reason is that these novel materials very often cannot be prepared as single crystals and their crystal structure has to be solved from polycrystalline samples, which is not always an easy task. The structural properties of selected doped nanomaterials which are of interest for technical applications, such as transparent conducting oxides (ATO and ITO), optoelectronic and luminescent materials (gahnite doped by cobalt, manganese or titanium) and doped ceramics (mullite doped by chromium or cobalt) have been studied. The samples were prepared by a sol-gel technique and investigated mainly by powder XRD. Their crystal structures were solved/refined using the Rietveld method, simultaneously with the size-strain analysis. Transmission electron microscopy, Mössbauer and EPR spectroscopy were performed as well, where appropriate. The aim of this research was to elucidate a mechanism of dopant atom incorporation in the starting material. Particular attention was paid to determination of the oxidation state and site of dopand in the structure of the doped material, and also to determination of the maximum doping levels of specific dopands in the given starting material.

Nanomaterials; Doped materials; X-ray diffraction; Structure; Microstructure

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